Automatic locking-crank.



o. c. RITTENHOUSE. AUTOMATIC LOOKING CRANK.

- APPLICATION FILED NOV. 15, 1909.

Patented June 27, 1911.

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CHARLES C. RIITENHOUSE, OF LOS ANGELES, CALIFORNIA.

AUTOMATIC LOCKING-CRANK.

To all whom it may concern:

Be it known that I, CHARLES C. RITTEN- HOUSE, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented new and useful Improvements in Automatic Locking-Cranks, of which the following is a specification.

' This invention relates to hoisting devices, and it is particularly applicable under conditions where a load is to be lifted or low ered as in the operation of a lift or elevator running between the floors of a building.

The object of the invention is toprovide an arrangement whereby the shaft or other member which raises the load is normally locked against movement in either direction; the driving member is provided with a controlling device by means of which the mechanism can be adapted at once for either raising the load or lowering it; for either direction of rotation the load is locked against a backward movement by a detent evlce.

The invention consists in the construction and combination of parts to be more fully described hereinafter, and particularly set forth in the claims.

I accomplish the above objects by means of the device described herein and illus trated in the accompanying drawings annexed hereto in which:

Figure 1 is a front elevation of the device. Fig. 2 is a plan showing parts of the device broken away. Fig. 3 is a rear elevation showing .the shaft in cross section. Fig. 4 is a transverse section through the shaft and particularly illustrating the duplex locking mechanism; this view also illustrates a permanent locking device which will prevent the device from being operated, part of the locking gear wheel being broken away.

,Referring more particularly to the parts 1 represents the case or barrel which is of circular form and provided on one side with a bearing 2 and an integral plate 3 by means of which the case may be secured to a support; through the bearing 2 the power shaft 4 extends, and this shaft is provided with a rigid gear wheel 5 which forms a cover for the case. The inner side of the circumferential wall of the case is provided with ratchet teeth 6, which have rounded points and which are rounded at their roots so as Specification of Letters Patent.

Application filed November 15, 1909.

to present rounded notches 7 in a series ex- Patented June 27, 1911. Serial No. 528,163.

tending continuously around the interior of the case, the shaft 4 is provided with a rigidly attached driving lever or crank 8 and in the outer extremity of this crank a 1 this sleeve 12 the shaft 9 is provided with a controlling lever 13, said lever 13 having a hub 14, which is secured to the rock shaft and from this hub 14 arms 15 project in opposite directions, the ends of these arms 15 are provided with knobs 16 for operating the rock shaft.

Near the inner face of the crank 8 a double lever 17 is rigidly attached, presenting arms extending in opposite directions and substantially at right angles to the crank 8. To the ends of this lever links 18 are attached. The lever 17 constitutes a main lever for controlling an auxiliary lever 19; this lever is pivotally attached on the bolt 20 near the inner end of the crank 8, it presents a pair of arms 21, which extend in opposite directions, but these arms are slightly inclined so that they present an obtuse angle toward the shaft 4, the outer ends of the arms 21 are provided with outwardly disposed extensions or handles 22 and to these handles 22 the links 18 aforesaid are attached. The outer ends of arms 21 are provided with pins 23 which pass through slots 24 which are formed in the gear wheel 5, said slots being disposed in a short arc about the pivot bolt 20; these pins 23 extend across the interior of the case 1.

On the interior of the case 1 a hub or block 25 is rigidly attached, at one side this block is extended so as to form sockets 26 to receive the butt ends 27 of pawls 28, these butt ends 27 are of circular form as viewed in side elevation so that they enable the pawls to rock as though pivoted. These pawls extend in opposite directions in a line substantially at right angles to the lever 8. The outer ends of the pawls are rounded so as to enable them to cooperate with the ratchet teeth 6 on the interior of the case 1. In order to maintain both pawls noranally in engagement with'the ratchet teeth I provide coiled springs 29, the outer ends of which are received in sockets 30 formed in the block or hub 25, the outer ends of these springs thrust against recesses 31 formed on the rear sides of the pawls as shown most clearly in Fig. 4:, as shown also in Fig. 4: pins 23 which constitute releasing devices for the pawls lie near the inner sides or edges of the pawls. On account of the arrangement shown in Fig. 4 it will be seen that the pawls 28 present themselves in opposite relation with respect to the ratchet teeth 6 so that under normal conditions one of the pawls will prevent a rotation of the shaft in one direction, while the other pawl will prevent its rotation in the o posite direction. Either of the pawls may be disengaged from the ratchet teeth by means of the controlling lever 13, and the mode of operation of the mechanism in this respect will be presently described.

I provide means for permanently locking the shaft against rotation independently of the pawls 28 in order to prevent the device from being operated by meddlers; for this purpose on the rear side of the case 1 a bracket 32 is rigidly attached and this bracket is offset toward the forward face of the case at which point it forms a radially projecting guide arm 33, in this guide arm 33 a locking bolt 3t slides, in the inner end of this locking bolt are formed teeth 35 which engage with the teeth of the gear wheel 5, as indicated in Fig. 4, when in an engagement of this manner this bolt locks the gear wheel against rotation and consequently it locks also the crank 8 and the shaft 4 against rotation. The arm 33 and the bolt 34 are provided with registered openings 36 which enable a pad lock 37 or a similar lock to be applied, as indicated in Fig. 4c, this'lock 37 can only be opened by means of a key, which will be in the possession of the person having charge of the hoisting device, evidently when the bolt 34 is removed the rotation of gear wheel 5 will be unobstructed.

The mode of the operation of the hoisting device will now be described.

In this connection it should be understood that the case 1 is fixed and both of the pawls 28 are normally held in engagement with the ratchet teeth 6, one of the pawls operating to prevent rotation in one direction while the other operates to prevent rotation in the opposite direction. Referring to Fig. 4 suppose that the crank 8 is to be rotated in the right hand direction so as to communicate a similar rotation to the shaft 4, it will be evident that the lower pawl 28 will tend to prevent such a rotation, in order to release this pawl it will be necessary to rotate the controlling lever 13 slightly in the right hand 'direction, as in dicated by the arrow in Fig. 1, this movement produces a thrust in the lower link 18, so that the pin 23 which corresponds to it will move against the lower pawl in such a way as to push it back and disengage it from the ratchet teeth, the crank 8 can then be rotated in a right hand direction, the uppermost pawl 28 riding freely over the teeth 6 and operating as a detent pawl to prevent a backward rotation of the shaft. Ill'tlle practical operation of the device I find that the pawl can be released with greater facility, if the crank 8 is first pulled slightly backward, this slight movement of the lever will ease the pawl so that it will free its extremity more readily from the teeth 6 or from the notches 7.

lVith a device constructed as described it will be evident that at an instants notice the shaft can be rotated in either direction by means of the crank 8 so as to raise a load or lower a load in either case one or the other of the pawls will be in active opera tion so that the lever will always be running on its pawl, that is a detent pawl will be in constant operation to prevent the load from running down. Furthermore the device is specially advantageous when a counter-weight is employed which may be heavier or lighter than the load thus this device will prevent a downward movement of a load that is being lifted and it will prevent an upward movement of the load under the action of a counter-weight heavier than the load.

Having described my invention what I claim as new and desire to secure by Letters Patent is:

1. In a hoisting device in combination, a fixed member, a shaft rotatably mounted in said fixed member, a hub carried by said shaft, pawls carried by said hub cooperating with said fixed member to prevent the rotation of said shaft in either direction, means tending to hold said pawls in engagement, a crank for rotating said shaft, a member pivotally mounted on said crank near said pawls and adapted to engage said pawls to release the same, and a controlling lever connected with said member and mounted on said crank.

2. In a hoisting device in combination, a case adapted to be fixed, a shaft rotatably mounted in said case, a hub carried by said shaft within said case, a cover for said case through which said shaft passes, pawls carried by said hub and cooperating with said case to prevent the rotation of said shaft in either direction, a crank for rotating said shaft, a double lever pivotally mounted on said crank, said cover having openings therein, pins carried by said double lever passing through said openings and adapted to engage said pawl to release the same from said case, a handle on said lever, and means adjacent to said handle for controlling said double lever.

3. In a hoisting device in combination, a fixed case, a shaft rotatably mounted in said case, a hub carried by said shaft within said case, pawls carried by said hub and coiiperating with said case to prevent the rotation of said shaft in either direction, a crank attached to said shaft for rotating the same, a rock shaft carried by the end of said crank and forming a handle for rotating said crank, means attached to said rock shaft for rotating the same, pins passing transversely of said pawls and adapted to strike the edges thereof to disengage the same from said case, means for guiding said pins, and means connecting said rock shaft with said pins for actuating the same.

4. In a hoisting device in combination, a fixed case having a rim with ratchet teeth on the inner side thereof, a shaft rotatably mounted in said case, a hub carried by said shaft within said case, pawls mounted in said hub projecting in opposite directions and adapted to engage said ratchet teeth at their extremities, springs thrusting against said hub and against said pawls normally maintaining said pavvls in engagement with said rim, said hub having means for retaining said springs, a crank rigidly attached to &

said shaft, a double lever mounted to rock on said crank adjacent to said case, pins carried by said double lever lying adjacent to the edges of said pawls and adapted to disengage said pawls from said rim, a handle on the outer end of said crank for rotating the same, and means carried by said crank for actuating said double lever to disengage either of said pawls.

5. In a hoisting device in combination, a fixed member having ratchet teeth, a shaft rotatably mounted in said fixed member, a hub carried by said shaft, pawls carried by said hub, cooperating with said teeth to prevent the r'otation of said shaft in either direction, means tending to hold said pawls in engagement with said ratchet teeth, a crank for rotating said shaft, a member pivotally mounted on said crank near said pawls, and adapted to engage said pawls to release the same, and a controlling lever connected with said member and mounted on said crank.

In witness that I claim the foregoing I have hereunto subscribed my name this 8th day of November, 1909.

CHARLES C. RITTENHOUSE.

Witnesses:

EDMUND A. STRAUSE, ETHEL COLEMAN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. O. 

